1. Field of the Invention
This invention relates to the structure of gear trains in electronic timepieces that utilize an electrical to mechanical transducer.
2. Description of the Prior Art
FIGS. 1 and 2 illustrate a prior art electronic timepiece that uses an electrical to mechanical transducer. In the prior art electronic timepiece of FIGS. 1 and 2, a quartz crystal oscillator and a stepping motor are used. In FIGS. 1 and 2, 1 is the base plate, 2 is the receptor, 3 is the motor coil, 4 is the rotor that includes a toothed claw 4.sub.a on rotor 4 and a permanent magnet 4.sub.b, 5 is the fourth wheel, 6 is the third wheel, 7 is the second wheel, 8 is the cannon pinion which is coupled to the second wheel 7 by friction, 9 is the back side minute wheel, 10 is an hour wheel, 11 is a setting wheel, 12 is the battery, 13 is the quartz crystal oscillator and IC circuits that are subject to pending vibration, and 14 is the stator of the motor. In the prior art electronic watch, the rotational motion of rotor 4 is passed through the so-called front side wheel chain that consists of fourth wheel 5, third wheel 6 and the second wheel 7 for the purpose of speed reduction. The rotational motion of rotor 4 is then transmitted to the so-called back wheel chain via the cannon pinion 8 and rotates the back side minute wheel 9 and the hour wheel 10. The cannon pinion 8 and the hour wheel 10 rotate the indicator hands (not shown). The numeral 15 indicates the dial washer.
Because of this construction, the front side wheel chain requires a great deal of space, and furthermore, it is located on the same level as the battery 12, creating a further obstacle to the miniaturization and thinner design of timepieces.